reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/esmil/linux/commit/b2bc5cdcd76cb7415d2ca5cce5f25056543f8473
        git remote add esmil https://github.com/esmil/linux
        git fetch --no-tags esmil d1-6.8.y
        git checkout b2bc5cdcd76cb7415d2ca5cce5f25056543f8473
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash arch/riscv/kvm/ drivers/gpu/drm/ drivers/net/ethernet/cadence/ drivers/nvme/host/ drivers/opp/ drivers/pmdomain/ drivers/scsi/ drivers/thermal/ drivers/usb/core/ drivers/usb/gadget/function/ drivers/usb/musb/ drivers/usb/phy/ drivers/video/backlight/ drivers/video/fbdev/core/ drivers/virtio/ fs/btrfs/ fs/lockd/ fs/nfs/ net/sunrpc/